Comparative study on scintillation properties of LGG, YGG and GGG

The scintillation properties of undoped Lu₃Ga₅O₁₂ (LGG), Y₃Ga₅O₁₂ (YGG) and Gd₃Ga₅O₁₂ (GGG) crystals were investigated at room temperature. All crystals resulted in around 70-80% transmittances in wavelengths 300 nm-500 nm. In addition, GGG crystals showed a weak absorption peak around 280 nm possibility due to Gd³⁺ 4f-4f absorption. These crystals had intrinsic luminescence peaks. The peaks of LGG, YGG and GGG crystals appeared among 300 to 400 nm. The light yields of LGG crystals were about 1,050 photons/5.5 MeV-α and YGG crystals were about 330 photons/5.5 MeV-α. In GGG, no noticeable peaks appeared. The scintillation decay time of LGG crystals radioluminescence spectra turned out to be of 1.71 ns under X-ray eicitation.